Diversity of insects in insecticide treated sweet corn ecosystem

Maize (Zea mays L.) is an annual cereal crop grown for supplementation of diet for human. Cultivation of sweet corn in Bangladesh is increasing with different hybrid varieties, and the crops are infested by fall armyworm. Farmers apply different insecticides to overcome the attack of fall armyworm without considering the impact of the insecticides on the diversity of pest and beneficial insect species. This study was undertaken from November 2023 to April 2024 to evaluate the effectiveness of eight different insecticides for managing fall armyworm in a sweet corn variety BU sweet corn 1 field, and investigated the biodiversity of the insects species in the sweet corn ecosystem. A total of 19 insect species were identified belonging to 17 families of 7 orders. The highest percentage was observed in minor pest (41%) followed by major pest (31%) and lowest was the beneficial insects (11%). In case of taxonomic orders, the highest abundance (24.3±3.3), richness (3.9±0.0), dominance (1.0±0.0) and diversity (0.7±0.0) were observed in Lepidoptera, Hemiptera, Ephemeroptera and Lepidoptera, Diptera order respectively. Vayego 20SC+Bio-chamak 1% E.W. yielded the highest beneficiary insect abundance (11.0±0.6), while control had the most minor insects (42.7±1.2) but Nitro 505EC alone attracted the highest casual insect count (16.3±0.9).